package test;

public class ConversionAlphaNumericUtil {  
	  
    private static final String baseDigits = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";  
    private static final int BASE = baseDigits.length();  
    private static final char[] digitsChar = baseDigits.toCharArray();  
    private static final int FAST_SIZE = 'z';  
    private static final int[] digitsIndex = new int[FAST_SIZE + 1];  
  
    static {  
        for (int i = 0; i < FAST_SIZE; i++) {  
            digitsIndex[i] = -1;  
        }  
        //  
        for (int i = 0; i < BASE; i++) {  
            digitsIndex[digitsChar[i]] = i;  
        }  
    }  
    
    public static void main(String[] args) {
    	for(int i=10; i<=99; i++) {
    		String numStr = "1497348270742" + "" + i;
    		long num = Long.parseLong(numStr);
    		String s= encode(num);
    		System.out.println(num);
    		System.out.println(s);
    		//System.out.println(decode(s));
    	}
//    	String numStr = System.currentTimeMillis() + "" + Math.round(Math.random() * 89 + 10);
		
	}
  
    public static long decode(String s) {  
        long result = 0L;  
        long multiplier = 1;  
        for (int pos = s.length() - 1; pos >= 0; pos--) {  
            int index = getIndex(s, pos);  
            result += index * multiplier;  
            multiplier *= BASE;  
        }  
        return result;  
    }  
  
    public static String encode(long number) {  
        if (number < 0)  
            System.out.println("Number(Base62) must be positive: " + number);  
        if (number == 0)  
            return "0";  
        StringBuilder buf = new StringBuilder();  
        while (number != 0) {  
            buf.append(digitsChar[(int) (number % BASE)]);  
            number /= BASE;  
        }  
        return buf.reverse().toString();  
    }  
  
    private static int getIndex(String s, int pos) {  
        char c = s.charAt(pos);  
        if (c > FAST_SIZE) {  
        	 System.out.println("Unknow character for Base62: " + s);  
        }  
        int index = digitsIndex[c];  
        if (index == -1) {  
        	 System.out.println("Unknow character for Base62: " + s);  
        }  
        return index;  
    }  
}  